Set up integrations after the app's initializers, and stop Shrine, AMS and Puma writing text lines - #18

AMS attaches a log subscriber that writes "Rendered UserSerializer with
ActiveModelSerializers::Adapter::Attributes (0.1ms)" for every render,
so each render was logged twice: once as that line of text and once as
LogStruct's structured ams.render line.

The logstruct.setup initializer only had to run before the middleware
stack was built, so it ran before the app's config/initializers. The
documented place to configure LogStruct is config/initializers/
logstruct.rb, so its integration toggles were ignored, and filters that
other initializers added to filter_parameters (such as Rails' default
filter_parameter_logging.rb) were never merged into LogStruct's filters.
It now runs after :load_config_initializers.

`config.enabled` and `config.enabled_environments` set in an
initializer were ignored too, because LogStruct decides whether it's
enabled when it's required, and the logger is replaced as soon as Rails
creates it. The logger is still replaced early, so boot-time logs and
code that keeps a reference to Rails.logger use it, but setup now
replaces it late if an initializer enabled LogStruct, and puts the
original loggers back if an initializer disabled it. As documented,
LOGSTRUCT_ENABLED takes precedence, then `enabled`, then
`enabled_environments`.

Inside LogStruct::Integrations::GoodJob, `GoodJob` is that module, so
the integration set the logger and thread error handler on itself and
GoodJob kept its own logger. It now sets them on ::GoodJob. The thread
error handler calls the handler the app set first (GoodJob's README sets
one to report errors), then logs the error.

Integrations are now set up after config/initializers, so Sidekiq kept
its own text logger while they ran. An initializer that configures
Sidekiq logs with that logger straight away (connecting to Redis,
setting up a fetcher), so those lines were plain text. The Railtie now
replaces Sidekiq's logger as soon as it replaces Rails.logger, and puts
Sidekiq's logger back if an initializer turns LogStruct or the Sidekiq
integration off.

Puma::ErrorLogger writes request errors (an exception the app didn't
handle, a malformed request, an SSL error) as a plain text line on
STDERR: the time, the request line with its query string and client
IP, and the error. LogStruct's Puma integration now logs them as error
lines (src puma, evt error) with the error, method and path. The query
string is left out, since tokens in it can't be filtered inside the
line.

The puma lifecycle initializer wrote "[logstruct] puma lifecycle init"
to STDERR on every rails server boot.